Take advantage of your perks – life, dental, and especially health insurance – to protect yourself and your finances. (If you don't get benefits through a job, head to HealthCare.gov.) I opted out of a $7 per month dental plan at my first job...only to get a cavity and a huge bill!

You Picked The Wrong Plan

Consider the true cost of a health plan: not only monthly premiums but also copays, prescriptions, deductibles (how much you pay before the plan kicks in), and coinsurance (the percentage you cover after it kicks in). Look for a plan with a lower deductible, especially if you have a chronic health issue, see a specialist, take brand name meds, or might get pregnant. Consider high out-of-pocket costs only if you're healthy and can't afford better coverage....But remember, anyone can get sick or injured, and one trip to the ER can cost a lot.

You Re-Upped Without Thinking

Ninety percent of workers auto-enroll in the same health
plan each year, a 2014 study by Aflac found. The best way
to prepare for the unknown is to review your benefits and
make sure they still fit your needs.

You Didn't Team Up

If you live with a partner, you might save by becoming a dependent on your S.O.'s insurance (or vice versa). Plus, people under 26 can glom onto a parent's insurance. Be aware of differing open-enrollment periods.

You Pretended You'd Never Get Old

You're going to work for roughly 50 years to support 70(ish) years of your life — the earlier you start saving for retirement, the better. Aim to contribute at least 5 percent of your base salary monthly by age 25 and 10 percent by age 30 to an employer-sponsored 401(k). If you're not enrolled at work, try a Roth IRA, which you can open online. Don't touch a penny in your retirement accounts before age 591⁄2 to avoid a major hit from taxes and penalties.

You Neglected Your Money

Just because you won't use your retirement money soon doesn't mean you should ignore it. Set a calendar alert to check on your investments at least once a year — as you get older, you'll want to take less risk. Brokerage firms have free online retirement calculators that can help you find a good mix. And keep an eye on those funds after you leave your job. If you feel unorganized, combining all your retirement accounts into one (aka rolling them over) might help.

You Left Benefits Behind

Perks don't always vanish as soon as you give notice or lose
your job. Drop by HR to ask if any benefits will linger. In some
cases, a severance package can be negotiated to extend your
health and dental plans temporarily. Some companies will
provide at least 18 months of COBRA insurance — but you
cover the (high) cost.

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